U.S. patent number 4,098,043 [Application Number 05/820,507] was granted by the patent office on 1978-07-04 for joint seal.
This patent grant is currently assigned to Harry S. Peterson Company. Invention is credited to Samuel D. McCready.
United States Patent |
4,098,043 |
McCready |
July 4, 1978 |
Joint seal
Abstract
A hollow elastomeric seal member having a bottom wall
particularly formed to facilitate installation of the seal within
an expansible joint.
Inventors: |
McCready; Samuel D.
(Birmingham, MI) |
Assignee: |
Harry S. Peterson Company
(Pontiac, MI)
|
Family
ID: |
25230982 |
Appl.
No.: |
05/820,507 |
Filed: |
August 1, 1977 |
Current U.S.
Class: |
52/396.06;
277/645; 404/47; 404/64; 404/65 |
Current CPC
Class: |
E01C
11/106 (20130101) |
Current International
Class: |
E01C
11/10 (20060101); E01C 11/02 (20060101); E01C
011/10 (); E04B 001/62 () |
Field of
Search: |
;52/396,403,573
;404/47,64,67,69,65 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
974,110 |
|
Sep 1975 |
|
CA |
|
1,437,682 |
|
Mar 1966 |
|
FR |
|
Primary Examiner: Perham; Alfred C.
Attorney, Agent or Firm: Reising, Ethington, Barnard, Perry
& Brooks
Claims
What is claimed is:
1. A joint seal comprising an elastomeric tubular structure having
a pair of laterally spaced planar side walls, a nonplanar upper
wall interconnecting the upper ends of said side walls, and a
nonplanar lower wall interconnecting the lower ends of said side
walls, said lower wall including a first pair of angularly related
linear wall sections interconnected at one pair of ends and
laterally spaced at the other ends to define a downwardly opening V
centrally of said side walls, first and second linear compression
bars respectively connecting the spaced other ends of the angularly
related wall sections with said side walls at points below the
vertical midpoints of said side walls, said lower wall including a
second pair of linear sections respectively projecting from
proximate the lower ends of said side walls to points intermediate
the ends of the first and second compression bars, said first pair
of angularly related wall sections moving into abutting
relationship after initial lateral compression of said seal.
2. A joint seal as set forth in claim 1 wherein said first pair of
angularly related wall sections are moved into abutting
relationship when the seal is laterally compressed by approximately
15% from its uncompressed state whereby said compression bars will
resiliently resist further lateral seal compression.
3. A joint seal as set forth in claim 1 wherein the distance
between the spaced ends of said first pair of angularly related
wall sections does not exceed 30% of the distance between said side
walls when the seal is uncompressed.
4. A joint seal comprising an elastomeric tubular structure having
a pair of laterally spaced planar side walls, a nonplanar upper
wall interconnecting the upper ends of said side walls, said upper
wall comprising a plurality of angularly related and interconnected
linear wall sections which terminate at their upper ends in
tread-like surfaces all of which are disposed in coplanar
relationship with the upper ends of said side walls, and a
nonplanar lower wall interconnecting the lower ends of said side
walls, said lower wall including a first pair of angularly related
linear wall sections interconnected at one pair of ends and
laterally spaced at the other ends to define a downwardly opening V
centrally of said side walls, first and second linear compression
bars respectively connecting the spaced other ends of the angularly
related wall sections with said side walls at points below the
vertical midpoints of said side walls, said lower wall including a
second pair of linear sections respectively projecting from
proximate the lower ends of said side walls to points intermediate
the ends of the first and second compression bars, said first pair
of angularly related wall sections moving into abutting
relationship after limited initial lateral compression of said
seal.
5. A joint seal as set forth in claim 4 wherein at least two of the
angularly related linear wall sections of said upper wall
respectively terminate at their lower ends at the junctions of said
first and second compression bars with said side walls.
6. A joint seal as set forth in claim 5 wherein two angularly
related wall sections of said upper wall respectively extend from
proximate the upper ends of said side walls to points intermediate
the ends of the two upper wall sections which terminate at one end
at the junctions of said compression bars with said side walls.
7. A joint seal comprising an elastomeric tubular structure having
a pair of laterally spaced planar side walls, a nonplanar upper
wall interconnecting the upper ends of said side walls, said upper
wall including a pair of downwardly curving arcuate wall sections
terminating in a common juncture centrally of said planar side
walls, and a nonplanar lower wall interconnecting the lower ends of
said side walls, said lower wall including a first pair of
angularly related linear wall sections interconnected at one pair
of ends and laterally spaced at the other ends to define a
downwardly opening V centrally of said side walls, first and second
linear compression bars respectively connecting the spaced other
ends of the angularly related wall sections with said side walls at
points below the vertical midpoints of said side walls, said lower
wall including a second pair of linear sections respectively
projecting from proximate the lower ends of said side walls to
points intermediate the ends of the first and second compression
bars, and an internal truss structure disposed within the volume
defined by the upper and lower nonplanar walls and the planar side
walls, said truss structure including a pair of web members
respectively extending between said downwardly curving upper wall
sections and the juncture of said compression bars with said side
walls, said first pair of angularly related wall sections moving
into abutting relationship after limited initial lateral
compression of said seal.
8. A joint seal as set forth in claim 7 wherein said internal truss
structure includes a second pair of web members respectively
extending between the downwardly sloping sections of the upper wall
and the first and second compression bars.
9. A joint seal as set forth in claim 8 wherein said internal truss
structure includes a third pair of web members extending
respectively between the second pair of web members and the apex of
the downwardly opening V of said lower wall.
Description
The present invention relates to a new and improved elastomeric
device for sealing the space between a pair of thermally expansible
structural members which must initially be assembled in a
nonabutting or non-contacting relationship. Such structural members
are typified by reinforced concrete slabs used in the construction
of roads, buildings or surface decks as in multistory parking
structures. While such concrete slabs are rigid and high-load
bearing members, they will expand and contract from less than an
inch to several inches depending on changing ambient temperatures.
Accordingly, it is normal practice to leave gaps or spaces between
adjacent slabs and to fill such space with elastomeric members
which are intended to seal the space between such slabs as the
distance therebetween varies with temperature.
BACKGROUND
A variety of elastomeric seals have been developed to protect
structural expansion joints against leakage as the joint opening
varies with changes in ambient operating conditions. Such joint
seals include numerous forms of peripheral and internal truss
structures which cause the seal to function in a particular manner
to seal a joint during the expansion and contraction of the
associated structural members.
In addition to withstanding frequent flexure due to the expansion
and contraction of the associated structural members, it is also
frequently necessary for such joint seals to withstand transient
deck loads imposed by vehicular or pedestrian traffic. Thus, it is
necessary that such joint seals have sufficient strength and
flexibility to elastically recover from both transverse movement
and vertical flexure.
It is commonly required that such joint seals be compressible up to
at least 50% of their uncompressed or free-state form without
losing their ability to reexpand to their installed shape and size
when such compressive forces are diminished.
SUBJECT INVENTION
It is the purpose of the present invention to provide an
elastomeric joint seal which, while being able to withstand
transverse movement and vertical flexure, also includes a unique
construction which facilitates easy installation of the seal
without depreciating its ability to recover or reexpand as such
loads are lessened or relieved.
More specifically, the subject seal includes a pair of
substantially parallel and planar side walls which are
interconnected at their upper and lower ends by nonplanar and
particularly formed upper and lower walls. It is also an object of
the present invention to provide a uniquely formed bottom seal wall
which permits relatively easy and limited initial transverse
compression of the seal to facilitate its installation within a
joint. The bottom wall of such seal is so formed that while having
a relatively low initial resistance to transverse compression for
easy of installation, the resistance to transverse compression
increases perceptibly following installation of the seal in the
joint.
The uniquely formed bottom seal wall also coacts through an
internal truss structure to support the upper nonplanar wall so as
to maintain an upper seal configuration which has a minimum
vertical displacement or distortion relative to that which exists
at the time of installation.
Other objects and advantages of the present invention will be
apparent from the detailed description which follows.
In the drawings:
FIG. 1 is an elevational view of a first modification of the
invention;
FIG. 2 is an elevational view of the seal as initially installed in
the space between two structural members;
FIG. 3 is an elevational view illustrating the seal compressed to
about 40% of its uncompressed or free-standing width;
FIG. 4 is an elevational view of a second modification of the seal;
and
FIG. 5 is a load/deflection diagram of the seals of the types shown
in FIGS. 1 and 4.
FIGS. 1 through 3 relate to a first modification of the invention.
The seal is indicated generally at 10 and the structural members
defining the joint to be filled by the seal are indicated at 12 and
14. The most common use for seals of the type shown in the subject
invention is in combination with structural members 12 and 14
formed of pre-stressed concrete as used in parking decks,
sidewalks, building flooring and the like and where such seals or
expansion joints are able to compensate for the lateral thermal
expansion between the structural members while still maintaining
the integrity or impermeability of such joints. It is basically
required of such seals that they fill the joint between the
structural members so as to accommodate thermally induced changes
in the size of such joint while maintaining joint impermeability to
water, dirt, and other debris throughout the thermal cycling of the
joint.
Inasmuch as seal 10 is commonly used in installations subjected to
either or both vehicle and pedestrian traffic, it is also
imperative that the seal be of such a construction as not to bulge
or be vertically distended at its top surface so as to provide an
impediment to such traffic. In other words, even though seal 10 is
designed to be transversely compressible to 50% or more of its free
formed or uncompressed width, the upper and lower non-planar
surfaces of the seal should not be significantly vertically
distensible or deformable from its initially installed
position.
It is also to be noted that the elastomeric seal of the present
invention must be of the type as can be continuously extruded and
cured so as to enable the joint seals to be cut to the exact length
necessary to fill a particular joint and thereby avoiding the
necessity of utilizing spliced or cemented joints in the field
which are highly susceptible to breaking or being mis-matched after
installation.
It is imperative in the design of the seal of the subject invention
that it be formed in such a manner as to have sufficient internal
resilience or strength as to insure that the seal can recover to
its installed sealing condition as the seal is cycled from minimum
to maximum compression over many years of use. In other words,
while an elastomeric seal can be made which would be easy to
install in a joint, the internal structure of the seal might be
such as to have inadequate elastomeric or resilient recovery
through the period of use required for such seal. It is thus a
primary purpose of seals made in accordance with the subject
invention to permit relatively easy initial installation of the
seal within a joint and yet which seal is able to maintain the
sealed integrity of the joint over the expected life of the seal.
Referring specifically to FIG. 1 of the drawings, seal 10 is
extruded of a suitable elastomeric material such as DuPont's
Neoprene which is a thermosetting polymer generically known as
polychloroprene mixed with carbon black, process oil, and other
necessary rubber chemicals such as anti-oxidants, anti-ozonants and
a curing agent. While the invention is in no way limited to a
specific elastomer, the aforementioned material is one that has
proven to be very satisfactory for seals of the type comprehended
by the subject invention.
Seal 10 is of an enclosed or tubular construction and is adapted to
be extruded in the form shown in FIG. 1 and which forming process
includes extruding the seal in a "green" or uncured state followed
as quickly as possible by a vulcanization of continuous curing
process which gives the seal its final structural strength. Seal 10
includes a pair of planar and substantially parallel side walls 16
and 18, a nonplanar upper wall indicated generally at 20, and a
nonplanar lower wall indicated generally at 22. The upper and lower
walls 20 and 22 extend between the upper and lower ends of side
walls 16 and 18. When using the expression "nonplanar", it is meant
to refer to surfaces which are not flat and continuous as are side
walls 16 and 18. In the modification of FIG. 1, it is also to be
noted that the height of side walls 16 and 18 is less than the
transverse distance between the side walls, which relationship also
contributes to ease of initial installation. While the invention is
not to be limited to specific dimensions, a typical seal of the
type shown in FIG. 1 might have a width of 5 inches and a height of
3 inches.
The configuration of bottom seal wall 22 is substantially identical
in the modifications shown both in FIG. 1 and FIG. 4. Likewise, the
side walls 16 and 18 are substantially identical in both
modifications. On the other hand, the upper wall configuration 20
of FIG. 1 is different from that indicated generally at 86 in the
seal 84 depicted in FIG. 4.
As will hereinafter be pointed out in greater detail, the nonplanar
lower seal wall 22 is comprised of an interconnected series of
linear sections symmetrically disposed about a vertical center line
midway between side walls 16 and 18. Bottom wall 22 includes a
first pair of linear sections 24 and 26 interconnected at their
upper ends and transversely spaced at their lower ends so as to
define a downwardly opening V. The apex of the downwardly opening V
is generally coincident with the vertical mid-axis of the seal.
First and second linear compression bars 28 and 30 extend upwardly
and outwardly from the spaced ends of linear sections 24 and 26 and
respectively intersect with side walls 16 and 18 intermediate the
upper and lower ends thereof. Visualizing a horizontal seal axis
midway between the upper and lower ends of side walls 16 and 18, it
is to be noted that the juncture of compression bars 28 and 30 is
below such horizontal axis.
A pair of short linear bottom wall sections 32 and 34 extend
horizontally from the lower ends of side walls 16 and 18 and
terminate respectively between said side walls and the downwardly
opening V of lower wall 22. A pair of linear wall legs 36 and 38
respectively extend upwardly from the inner ends of horizontal
bottom wall sections 32 and 34 to intersect compression bars 28 and
30 intermediate the ends thereof. Thus, bottom seal wall 22 is
comprised of linear sections 32, 36, 28, 24, 26, 30, 38, and
34.
Still referring to the modification of FIG. 1, upper seal wall 20
includes a plurality of angularly related linear sections 40, 42,
44, 46, 48, 50, 52, and 54. Linear sections 46 and 48 intersect in
vertical alignment above the apex of the downwardly opening V of
lower wall 22. The intersection of linear sections 46 and 48 is
flattened at its top to provide a treadlike surface 56. Linear
sections 46 and 48 extend downwardly and outwardly to intersect
respectively at their lower ends with compression bars 28 and 30 at
the same point of juncture therewith as upwardly extending sections
or legs 36 and 38 of lower wall 22.
Similarly, upper wall sections 42-44 and 50-52 converge to form
treadlike surfaces 58 and 60. Short linear sections 62 and 64
extend horizontally from the upper ends of side walls 16 and 18 and
intersect respectively with downwardly and inwardly projecting wall
sections 40 and 54 to form treadlike surfaces 66 and 68. Downwardly
and inwardly extending upper wall sections 40 and 54 respectively
terminate intermediate the ends of downwardly and outwardly
extending linear sections 42 and 52, the latter which intersect
with side walls 16 and 18 proximate the junction therewith of
compression bars 28 and 30.
As best seen in FIG. 1, the treadlike sections 66, 58, 56, 60, and
68 of upper wall 20 are disposed in a generally coplanar
relationship.
Referring now to FIG. 2 of the drawings, seal 10 is disposed in the
opening defined by the laterally spaced structural members 12 and
14. Structural members 12 and 14 include oppositely facing planar
surfaces 70 and 72 and inwardly extending projections 74 and 76
which provide surfaces upon which the horizontal sections 32 and 34
of lower seal wall 22 can seat within the joint opening. As thus
seated within the joint opening formed between structural members
12 and 14, the treadlike surfaces of upper seal wall 20 are
disposed slightly below the upper surfaces 78 and 80 of such
structural members. Thus, the upper nonplanar wall 20 of seal 10 is
adapted to be slightly recessed with respect to the upper exposed
surfaces 78 and 80 of the structural members in order that the seal
not project above the structural members and thereby avoiding an
impediment to vehicular or pedestrian traffic.
In thus initially installing seal 10, as indicated in FIG. 2, the
seal is transversely compressed approximately 15% of its free
formed or uncompressed width as indicated in FIG. 1.
During the initial installation or 15% compression of seal 10,
bottom seal wall 22 more or less articulates about the apex of its
downwardly opening V and thus provides relatively low resistance to
such initial compressive action. Accordingly, seal 10 can be
manually transversely compressed to permit its insertion in the
seal joint. During the initial insertion compression of seal 10, as
depicted in FIG. 2, there is relatively little distortion of the
upper and lower seal walls 20 and 22.
By reference now to the load deflection curve A shown in FIG. 5
which represents the compressive forces on seal 10 at different
amounts of deflection, it will be noted that as the deflection of
the seal progresses up to about 15%, the transverse loading of the
seal expressed in pounds per linear inch remains low and relatively
constant at approximately 5 pounds per inch. As the structural
members 12 and 14 thermally expand from the initial installation
position of FIG. 2 toward the positions indicated in FIG. 3, linear
sections 24 and 26 of lower wall 22 reach an abutting position
substantially closing the downwardly opening V and thereby bringing
compression bars 28 and 30 into linear abutment with each other.
This initial point of contact between the compression bars is
depicted on the graph of FIG. 5 as occuring between the 15 and 20%
deflection points and depicts a distinct increase in the transverse
load on the seal. At such point of abutment between the compression
bars 28 and 30, the compression load on the seal steps up from
approximately 5 pounds per linear inch to approximately 10 pounds
per linear inch.
With reference to FIG. 3, seal 10 is compressed to approximately
40% of its free formed or uncompressed shape as depicted in FIG. 1.
Referring again to curve A of FIG. 5, it will be noted that at 40%
deflection the compressive load on the seal has increased to
approximately 15 pounds per linear inch. While the lower wall 22 of
seal 10 undergoes substantial distortion when subjected to
approximately 40% deflection, as illustrated in FIG. 3, it will be
noted that upper wall 20 undergoes relatively little distortion
other than the moving together of the threadlike surfaces which
also tend to tilt slightly during severe seal compression. Further
compression of seal 10 beyond the 40% deflection illustrated in
FIG. 3 will not significantly alter the amount of distension of
upper wall 20 and wherein the treadlike portions thereof do not
depart appreciably from their original coplanar relationship and in
no event do they project above the upper surfaces 78 and 80 of
structural members 12 and 14. It is also to be noted that even with
the severe seal compression of FIG. 3, upper and lower walls 20 and
22 do not distend meaningfully vertically beyond the upper and
lower ends of side walls 16 and 18.
Reference is now made to the modification of FIG. 4 wherein the
seal is generally indicated at 84. In this modification the lower
wall and the linear sections of which it is comprised are the same
as those shown and described with respect to FIGS. 1 through 3.
Accordingly, prime marks have been added to the numerals of FIG. 1
to indicate like members. Thus, the description of the components
bearing the primed numbers is the same as that made with respect to
FIGS. 1-3.
The primary difference between seals 10 and 84 relates to the shape
or configuration of their upper walls. In the case of FIG. 4, upper
wall 86 is comprised of two inwardly and downwardly curved sections
88 and 90 which converge at a centrally depressed juncture
vertically spaced above the apex defined by intersecting sections
24' and 26' of lower wall 22'.
The internal truss structure of seal 84 includes a first pair of
downwardly and outwardly extending cross bars 92 and 94 which
respectively intersect upper wall sections 88 and 90 at their upper
ends and terminate at their lower ends with side walls 16' and 18'
immediately above the juncture therewith of compression bars 28'
and 30'. A second pair of downwardly and outwardly extending cross
bars 96 and 98 extend between the centrally depressed region of
upper wall 86 and compression bars 28' and 30' opposite the
junction therewith by upwardly extending bottom wall sections 36'
and 38'. A third pair of cross bars 100 and 102 converge at their
lower ends with the apex of the downwardly opening V formed by
lower wall sections 24' and 26'. The upper ends of cross bars 100
and 102 intersect respectively with cross bars 96 and 98 proximate
upper wall 86.
The configuration of lower wall 22' of seal 84 from initial
insertion of the seal in a joint through the seal's compression is
substantially identical with that of seal 10 as depicted in FIGS. 2
and 3 of the drawings.
On the other hand, as seal 84 is transversely compressed, the
depressed central juncture between upper wall sections 88 and 90
moves progressively downwardly whereby the downward curvature of
sections 88 and 90 increases. As transverse compression of seal 84
increases, thereby depressing the central section of upper wall 86,
wall sections 88 and 90 move into progressively increasing rolling
abutment with each other. Such downwardly rolling abutment of upper
wall sections 88 and 90 assures that upper seal wall 86 will not
project above the seal joint as the seal 84 is transversely
compressed.
Reference is now made to curve B of FIG. 5 which depicts the
load/deflection relationship of seal 84. In this case it will be
noted that the downwardly curving upper wall 86, in effect,
stiffens the seal or increases its resistance to transverse
compression. For instance, at a 15% deflection, the compression
load is approximately 15 pounds per linear inch with the result
that seal 84 would require more force for initial installation as
compared with that required for seal 10. However, it is also to be
noted from curve B that beginning at about 15% deflection, the
upward slope of curve B increases again, reflecting the initial
linear abutment of compression bars 28' and 30'. As with both seals
10 and 84, the provision of the centrally disposed, downwardly
opening central V section reduces the transverse force necessary
for initial installation of the seal in the joint between
adjacently disposed structural members such as 12 and 14.
It is to be understood that the buildup in compressive forces, as
depicted by curves A and B of FIG. 5, allows the seals 10 and 84 to
recover or reexpand as the joint opens.
In order to further enhance the impermeability of the sealed
joints, particularly to the passage of water, it is preferred to
utilize a urethane of neoprene based adhesive between the seal and
the structural members. More particularly, such adhesive is applied
to planar side walls 70 and 72 of the structural members 12 and 14.
Prior to curing, the adhesive also performs a lubricating function
to facilitate insertion of the seal within the joint formed by
structural members 12 and 14. After insertion, the adhesive will
cure thereby bonding the planar side walls 16 and 18 to the planar
surfaces 70 and 72 of structural members 12 and 14. It will be
appreciated that the greater the ability of the elastomeric seal to
return to a more expanded condition as thermal conditions cause the
joint to open, the less will be the tendency of the adhesive bond
between the seal and structural members to break down in use.
In the modifications of both FIGS. 1 and 2 the width of the open
end of the downwardly opening V is approximately 15% of the total
uncompressed width of the seal. Depending on the seal size, the V
opening may be up to 30% of the uncompressed width of the seal.
It is apparent that various modifications of seals may be made
within the intended scope of the invention as set forth in the
hereinafter appended claims.
* * * * *